(((kat))) - welcome to SR! I agree with ((Kindeyes)) - while he is working on him, this is the perfect opportunity to work on you.
I was in love with A's (alcoholic, then 2 addicts) for decades. Eventually, my way of dealing with it (totally wrong) was to begin using, became an addict myself and am in recovery.
It wasn't until I came here, that I realized MY "sticking by him, no matter what" actually contributed to the problem. I'm not saying the same is true for you, but it's something to think about.
You are right that rehab is only the first step. He will never be cured of addiction. He can, however, find recovery. I do believe in hope and prayer, but I also believe in looking at things realistically. I hope you read the other threads here. Granted, most are by people who have/are struggling and there really aren't many "success stories" but I think it will help you see what addiction is truly like.
There are success stories, but it requires both partners being true to themselves, trust and respect.
Hugs and prayers,
Amy